This paper presents the results of determination of artificial ¹³⁷Cs and natural ⁴⁰K activity concentrations in plants (bilberry (Vaccinium myrtillus) and moss ( Polytrichum commune ) Polytrichum commune )) and in soil samples from two main Tatra Valleys; Kościeliska and Rybi Potok Valley. The data were obtained during two years (2001- 02). These plants are known a as good bio-monitors for radioceasium [1,2 ]. It is known that ¹³⁷Cs and ⁴⁰K isotopes play important roles in the environment, due to their good assimilation by plants. The transfer of these elements from soil to plant depends of many factors: type of soil, organic matter contents, pH, type of plants. In this paper some results concerning the transfer of ¹³⁷ Cs and ⁴⁰K isotopes from various types of Tatra soil to moss or bilberry are shown.